iOS Application Security

13ENCRYPTION AND AUTHENTICATION

While Apple’s cryptographic APIs are fairly robust, many developers don’t know how to use them effectively. There are two major built-in encryption components that you have control over: the Keychain and the Data Protection API. These components share some of the same encryption keys and have similar protection attributes, and I’ll cover them in this chapter. I’ll also provide a look at lower-level crypto primitives and the (limited) circumstances in which you would want to use them.

Using the Keychain

The Keychain is meant to be used when you have small snippets of sensitive data to store, including passwords, personal data, and so on. The Keychain itself is encrypted using the Device Key, combined with a user ...